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A199762
a(n) = (9*11^n+1)/2.
1
5, 50, 545, 5990, 65885, 724730, 7972025, 87692270, 964614965, 10610764610, 116718410705, 1283902517750, 14122927695245, 155352204647690, 1708874251124585, 18797616762370430, 206773784386074725, 2274511628246821970
OFFSET
0,1
FORMULA
a(n) = 11*a(n-1)-5.
a(n) = 12*a(n-1)-11*a(n-2).
G.f.: 5*(1-2*x)/((1-x)*(1-11*x)).
MATHEMATICA
(9 11^Range[0, 20]+1)/2 (* or *) LinearRecurrence[{12, -11}, {5, 50}, 20] (* Harvey P. Dale, Sep 07 2023 *)
PROG
(Magma) [(9*11^n+1)/2: n in [0..30]];
CROSSREFS
Sequence in context: A113330 A079157 A286974 * A078244 A233068 A237020
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Nov 10 2011
STATUS
approved